Recently, surgeons have come more and more to the use of staple sutures, rather than conventional thread sutures, for closing wounds or incisions in the skin or fascia of a patient. This trend is due in part to the fact that the use of staples is a far easier procedure. Of even more importance, however, is that the use of surgical staples is very much faster. This substantially reduces the time required for suturing and the length of time the patient must be maintained under anesthesia.
Prior art workers have devised many types of surgical stapling instruments. Exemplary instruments are taught, for example, in U.S. Pat. No. 3,819,100 and U.S. Pat. No. 4,196,836.
Such surgical stapling instruments have a number of common drawbacks. First of all, they are relatively complicated in construction and design, with a plurality of moving parts. Such instruments, by virtue of their complexity, are subject to jamming, misformed staples and misfed staples. In general, they are bulky at the staple discharge end, thereby obstructing the surgeon's visibility. Their bulkiness and weight in the surgeon's hand may cause excessive fatigue when many staples are required to close a wound or incision.
U.S. Pat. No. 3,278,107 teaches surgical staple applying instruments in the form of a tweezer type instrument and a hemostat type instrument. Both instruments are provided with anvil portions. However, they are of the type wherein the surgical staple is clinched by the anvil portion, rather than formed thereabout.
Prior art workers have also devised numerous hemostatic-type surgical instruments for the application of ligator clips. Exemplary instruments of this type are taught in U.S. Pat. Nos. 3,270,745; 3,326,216; 3,439,523; 3,631,707 and 3,867,944. Instruments of this type, however, are used in a pliers-like fashion to clamp clips about tubular vessels and the like.
Heretofore, prior art workers have developed many types of cartridges for surgical staples. U.S. Pat. No. 3,618,842 teaches a surgical staple cartridge in which the staples are fed by a twin screw arrangement. A ratchet-driven surgical staple cartridge is described in U.S. Pat. No. 3,638,847. In U.S. Pat. No. 3,650,453 a surgical staple cartridge is taught wherein the staples are belt-fed. Finally, in U.S. Pat. No. 4,043,504 there is described a surgical staple cartridge wherein the staples are spring-fed.
These prior art surgical staple cartridges, of which the above noted patents are exemplary only, are generally characterized by complex construction and numerous moving parts. As a result, the opportunity for jamming or misforming of the surgical staples is increased. Such cartridges are normally mounted on the surgical stapling instrument itself. Due to their complex construction and bulkiness they further impede the surgeon's visibility and render it more difficult to accurately locate a surgical staple and see it being formed in the tissue.
Many of the above noted U.S. Patents dealing with instruments for applying ligator clips teach magazines for such clips which are wholly separate from the instruments themselves. Such magazines, however, are not suitable for use with surgical staples since surgical staples must be grasped in a different manner so that they can be clinched about an anvil surface, rather than simply being clamped shut, as in the case of ligator clips.
The above noted U.S. Pat. No. 3,278,107 teaches a surgical staple cartridge wholly separate from the applying instruments. In this instance, however, the cartridge is an elongated rectangular hollow member containing a plurality of spring-advanced capsules or housings, each containing a surgical staple. The stapling instrument engages and removes from the cartridge both a surgical staple and the capsule or housing containing it.
The present invention is directed to a surgical stapling system comprising a surgical stapling instrument and a wholly separate staple-carrying cartridge therefor.
The surgical stapling instrument itself is of very simple six-piece construction. It provides a staple pick-up and locking feature. The instrument is of sturdy, light weight, permanent construction capable of sterilization by any of the well known methods, and is virtually maintenance free. The instrument provides excellent visibility, enabling the entire staple to be seen with the result that accurate placement is very simple to achieve. The instrument cannot jam or misform the staple. The instrument can be completely assembled and disassembled in a matter of seconds without the use of tools. Finally, the instrument is adaptable to many different staple sizes.
The cartridge of the present invention is characterized by a very simple one-piece molded construction. The number of staples to be held in the cartridge is limited only by a practical and convenient length for the cartridge. The design itself is such that the size of staple to be housed in it and the wire size of the staple are not limiting factors.
The cartridge and the staples it contains may be sterilized or resterilized by any of the conventional methods. The cartridge lends itself well to a wide range of pre-sterile packaging.
The one-piece cartridge can be molded of appropriate plastic material in a variety of colors. Thus, the cartridge could be color-coded for quick identification of the size of the staples contained therein. The surgeon can readily ascertain at a glance how many staples remain in the cartridge at any given time. The cartridge may be provided with a pressure sensitive adhesive means on its bottom surface so that it can be removably affixed to any appropriate support, eliminating the necessity for the surgeon to hold the cartridge in his hand during the staple suturing procedure. Alternatively, the bottom of the cartridge may be configured to fit into an appropriate weighted base.
The cartridge of the present invention has means assuring that the anvil portion of the surgical stapling instrument will be properly centered under the crown of each surgical staple. Since the staples are held in place in the cartridge by an interference fit between the outer surfaces of the staple legs and the vertical inner surfaces of the ends of the staple slots, the cartridge can readily be shipped in a filled condition and will, nevertheless, provide for easy and positive removal of the staples from the cartridge. Finally, the cartridge is easily and inexpensively manufactured and, after use, the cartridge provides minimal disposable waste.